1. Field of the Invention
This invention relates to fasting devices. More particularly, this invention relates to fastening devices having increased structural integrity added thereto and which receive therein a resilient material for holding added fibers, the device being secured within an aperture of a workpiece as a result of the received material. This invention also relates to a fastening device for a multi-layered workpiece where the fastening material is injected after the device is in place.
2. Information Disclosure Statement
A common source of failure of conventional metallic fasteners is caused by the vibration or movement between the metallic fastening device and the metallic workpiece. This movement results in fatiguing and the wear of the metallic fastening device which enables further movement resulting in further deterioration of the fastening device. Various types of means and methods have been provided in the prior art for eliminating this undesired movement between a metallic fastening device and a metallic workpiece. Another source of failure is the weakening of the workpiece structure caused by a hard fastener being driven into a material. Another source of failure occurs when a hard fastener is inserted into a workpiece aperture having an irregular internal shape, or when there is to be movement between workpieces after fastening. Another source of failure, and one that is all too common, is the shearing of the fastener due to shear forces acting thereon over a period of time.
Some examples of patents which are pertinent to the instant invention include U.S. Pat. Nos. 207,871, 2,408,559, 2,410,398, 2,417,262, 2,453,994, 2,568,075, 2,677,149, 2,928,446, 2,989,107, 3,362,276, 3,293,977, 4,088,327, 4,140,742, 4,163,812, 4,183,974 and 4,189,369.
Although these prior art patents as well as U.S. Pat. Nos. 4,094,222, 4,100,954, 2,952,129 and 3,082,807 have solved some of the needs of the prior art, none of these patents have successfully provided a simple and efficient fastening device for securing within an aperture of a workpiece for reducing the undesired movement therebetween, or for securing workpieces having irregular-shaped apertures or for adding structural strength to a fastener.
Particularly in the aircraft industry, it has been customary to rivet juxtaposed plates together. These prior art rivets have often included a head portion protruding from the smooth surface of the plate being riveted. Such protruding heads not only detract from the aesthetic appearance of the aircraft, but more particularly present a resistance to air flow resulting in increased fuel costs and a reduction in maximum relative speed of the aircraft.
Although in the prior art various proposals have been disclosed for blind riveting aircraft plates having countersunk heads, these prior art proposals have necessitated the employment of relatively complex riveting equipment. Furthermore, a need has existed in the art for flexibly bonding together adjacent plates in the aircraft industry because it has been found that such flexible bonding reduces the amount of metal fatigue that has been associated with the prior art riveted plates.
The present invention provides a fastening device which enables a plurality of metal plates or laminae to be flexibly bonded together by means of a plurality of elongate members which define channels for the insertion therein of a thermo-setting resin or the like such that there is a clearance between the elongate members and the metal plates, the clearance being filled with the resin. The present invention also provides a fastening device which enables the bonding together of workpieces having irregular apertures, as well as workpieces where high shear loads are experienced.
In the fastening art, there are several examples of situations where structural integrity in the shear direction is mandatory. One such method of achieving such structural integrity is to add structural fibers oriented along the axis of the rivet fastener. However, in many situations this presents a problem particularly where the workpiece apertures are irregular or where there are many apertures not perfectly aligned one with the other. Another instance of difficulty is when the rivet is in place and it is desired to add structural fibers thereafter to give additional strength.
Therefore it is an object of this invention to provide an apparatus which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution of the advancement of the fastening art.
Another object of this invention is to provide a fastening device for securing within an aperture of a workpiece the device having a groove disposed along a longitudinally extending body member thereof for receiving a resilient material within the groove for co-acting between the body member and the workpiece for reducing undesired movement thereby.
Another object of this invention is to provide a fastening device for securing within an aperture of a workpiece incorporating a thermal liquifying material within the groove to seal the fastening device to the workpiece upon the application of heat. This same thermal material serves to bond fiber structural material to the fastening device.
Another object of this invention is to provide a fastening device for securing within an aperture of a workpiece including fibers as well as a thermal expandable material disposed within the groove of the fastening device to seal the fastening device to the workpiece upon the application of heat.
Another object of this invention is to provide a fastening device having structural fibers embedded thereon for securing within an aperture of a workpiece wherein a resilient material is injected between the fastening device and the workpiece after insertion of the fastening device into the aperture of the workpiece.
Another object of this invention is to provide a fastening device for securing within an aperture of a workpiece including an aperture extending through a fastener head of the fastening device and in fluid communication with the grooves extending along a longitudinally extending body member of the workpiece enabling a resilient material to be introduced through the fastening head aperture to fill the groove and region between the fastening device and structural fibers to add strength to the fastening device such that the workpiece does not shear the fastening device. The resilient material, in another embodiment is contained within the device and serves to mechanically lock the device and the structural fibers to the workpiece.
Another object of this invention is to provide a method of installing a rivet into an aperture of a workpiece by inserting the rivet into the aperture of the workpiece and deforming the rivet while the rivet is in the aperture of the workpiece by injecting a resilient material through a head aperture in the rivet to resiliently engage the rivet to the workpiece.
Another object of the present invention is to provide a fastening device for fastening together a multi-layered workpiece that overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which significantly contributes to the reduction in wind resistance of the fastened workpiece and the inhibition of metal fatigue.
Another object of the present invention is the provision of a fastening device having added structural fibers, the device adapted for the reception therein of a thermo-setting material in which the thermo-setting material is injected within a channel extending through the fastening device such that the thermo-setting material fills the interstices between the multi-layers of the workpiece, the individual structural fibers and the fastening device.
Another object of this invention is the provision of a method of adding structural fibers to a fastening device while still having the device flexible enough for insertion into a workpiece.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a further understanding of the invention may be had by referring to the summary of the invention and the detailed description describing the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.